1. Field of the Invention
This invention relates to a flow measuring device according to the principle of the Karman vortex path.
2. Description of the Prior Art
Devices for measuring flow are known. For example, U.S. Pat. No. 3,972,232 describes and claims such a device in which the choke body is constructed of a T-shaped structure having a relatively narrow prismatic forward part of trapezoidal cross-section and a following slab-shaped part of relatively large thickness. The means for measuring the pressure variations are arrangeed in the form of piezoelectric pickups in the slab-shaped part in such a manner that the pressure-sensitive surfaces are attached to the upper and lower side surfaces of the slab-shaped part and are parallel to the flow.
It has been found that, depending on the type of measuring medium and the flow velocity, the slap-shaped extension and with it, the outside surfaces of the pressure pickup arranged in the known measuring device are subject to the eroding influences, to dirt and deposits or a combination of these. The results are erroneous measurements.
It is therefore an object of this invention to provide a flow measuring device which provides accurate measurements.
It is also an object of this invention to provide a flow measuring device according to the principle of the Karman vortex path in which the structural configuration of the choke body is favorable for vortex separation and in which the surfaces containing or actuating the pressure pickups are positioned in a zone which is as undisturbed as possible.
Still other objects and advantages of the present invention will be obvious and apparent to those of skill in the art from the specification and the appended claims.